Ammunition for practice firearms



` May 3, 1966 R. w. KERR 3,249,048

AMMUNITION FOR PRACTICE FIREARMS Original Filed May 7, 1964 United States Patent Gfilice 3,249,048 Patented May 3, 1966 3,249,048 AMNIUNITION FOR PRACTICE FIREARMS Raymond W. Kerr, Box 4178, Lincoln, Nebr. @riginal application May 7, 1964, Ser. No. 365,701. Divided and this application Mar. 15, 1965, Ser.

4 Claims. (Cl. 1in-41) This application is a division of copending application Serialv No. 365,701, filed May 7, 1964, and entitled, Practice Firearms and Ammunition Therefor.

The present invention relates generally to firearms and ammunition and more particularly to firearms intended for training and practice use and ammunition of the safety type for use therein.

There is always the possibility in target practice with firearms, even if safety type ammunition is intended, that a standard or conventional round might be loaded into the firearm by mistake and fired. This is dangerous and is not unlikely to cause serious injury and even death. Yet it is desirable that firearms used for practice purposes be comparable in size, weight and balance with those using conventional ammunition.

Accordingly it is a general object of the present invention to provide safety fire arms and ammunition which are effective for training and practice purposes but which are selective in that the firing only of the safety ammunition is permitted and the firing of standard or conventional ammunition is precluded.

It is a mo-re specific object of the present invention to provide a safety round of ammunition which is not only readily distinguishable from a conventional round but the use of which requires the firearm to be selective to the extent that it can fire only the safety round.

A related object is to provide a safety firearm construction for yreceiving and firing a safety round, but which will not fire a conventional round that might be inserted therein accidentally.

It is a further object to provide an adapter for selectively converting a standard firearm for practice use with safety ammunition so that it can fire only safety rounds when so adapted, but which adapter can be readily removed to permit restoration of the firearm to its normal operating condition.

Other objects and ancillary advantages of the invention will be apparent from the following `detailed description -and upon reference to the accompanying drawings, in

ent invention so as to be capable of firing only safety ammunition.

FIG. 4 is a side elevation partly in section of a round of safety ammunition showing the cartridge and projectile separated; and

FIG. 5 is a rear elevational View of the round of safety ammunition shown in FIG. 4.

While the invention is described in connection with certain preferred embodiments, it will be understood that it is not thereby intended to limit the invention to those particular embodiments. On the contrary it is intended to cover all alternatives, modifications, and equivalents which may be included within the spirit and scope of the invention as defined in the appended claims.

Referring more particularly to the drawings, there is shown in FIG. 1 a piston type firearm 10 and a safety cartridge 11 embodying the present invention. The illustrative firearm 10 is intended for training and practice use and includes a frame 12 pivotally mounting a forwardly extending barrel 14 and having a depending stock or grip 15. As shown the firearm frame 12 and barrel assembly 14 are made of a suitable plastic material with the barrel being reinforced with a metal liner 16. A firing chamber, generally indicated at 18, is provided to receive the cartridge 11. The chamber 18 includes the rear portion of the barrel assembly 14 and its liner 16. The rear of the firing chamber 18 is ldefined by a recoil plate 20 which is carried by the frame 12.

The firearm 10 includes a firing mechanism for detonating the round 11. In the illustrative firearm the firing mechanism includes a firing pin 22 which is mounted upon a carrier 24 for longitudinal movement between cocked and firing positions. In the latter position the firing pin projects through an opening 25 in the recoil plate 2t) so as to engage and detonate the primer of a safety round 11 that is disposed within the firing chamber 18. The instant firing mechanism is shown merely for purposes of illustration and it will be apparent that any number of operable constructions can be used. In the illustrative firing mechanism the firing pin carrier 24 is longitudinally movable within a bore 26 formed in the upper rear portion of the frame 12. The carrier is biased toward firing position by means of a main spring 28, The main spring is compressed by manually withdrawing a cocking pin 29 which has a crosshead 30 at its forward end that is engaged in a slot 31 formed in the firing pin carrier 24. Upon withdrawing the cocking pin, .the crosshead 30 engages the rear end of the carrier slot 31 so that the carrier is pulled rearwardly within the bore 26, cornpressing the spring 28 and withdrawing the firing pin 22 in the aperture 25 in the recoil plate 20. Withdrawal movement is continued until the -cocked position of the firing pin carrier 24 is attained. To retain the carrier 24, and with it the firing pin 22, in cocked position a spring biased pawl 33 is provided for engagementin a notch 34 located adjacent the front end of the carrier 24. The cocking pin 29 is equipped with a light return spring 35 which, as shown, is disposed within the main spring 28 and about the cocking pin. The return spring is also compressed as an incident to withdrawal movement of the cocking rod. When the cocked position of the carrier is attained and the cocking pin is released, the return spring, which at its forward end engages the crosshead 30, serves to retract the cocking pin.

To release the carrier to the action of the main spring the frame is equipped with a trigger mechanism. This mechanism includes a trigger 36 which is mounted at the forward end of a slide 38 the latter being biased toward normal forwardly-extended position by means of an eX- pansion type spring 39. The trigger slide 3S is formed with an inclined rib 4f) and interposed between the rib and the pawl 33 is a push rod 41. The lower end of the push rod is complementally inclined and in engagement with the rib 40. Thus, when the trigger 36 is moved rearwardly upon being squeezed by an operator using the illustrative firearm, the slide rib 40 is effective to urge the push rod 41 upwardly to the end that the pawl 33 is rotated against the action of its biasing spring to release the firing pin carrier 24 to the action of the main spring 28, whereupon the carrier is driven forwardly `and the firing pin 22 is projected through the aperture 25 in the recoil plate 20 and into position for engagement with the primer of a safety cartridge 11 received in the firing chamber 18 so as to detonate the same.

Access to the firing chamber 18 to permit loading and unloading is in the illustrative firearm accomplished by breaking the barrel assembly 14 with respect to the frame 12 so as to pivot the barrel assembly downwardly.

To hold the barrel assembly in normal or closed position a spring biased detent 43 is provided in the frame 12 which is engageable in a complementally formed and juxtaposed recess 44 formed in the lower portion of the barrel assembly 14.

As shown, the barrel assembly includes an extractor 45 which is disposed at the rear end of the barrel assembly so that it engages the head of the cartridge. The extractor 45 is mounted for limited longitudinal movement upon an extractor rod 46 which in turn is spring biased so as to normally retain the extractor in forward position. The extractor 4S is operable to engage and urge the cartridge rearwardly, when the barrel assembly 14 is in open position with respect to the frame 12, a sufficient distance to permit the cartridge head to be grasped by an operators lingers and removed from the Vfiring chamber. Y

As hereinbefore noted the firing chamber 18 of the illustrative firearm 10, as shown in FIGS. l and 2, is defined in part by the barrel assembly 14 and in part by the recoil plate 29. More particularly, the rear portion of the liner 16 of the barrel assembly is utilized to receive the forward cylindrical portion of the casing of a round of ammunition and the portion of the projectile that extends therefrom. To define the rear portion of the chamber for receiving the head of the cartridge the recoil plate 20 has a forwardly opening recess 50 formed therein. It is into this recess that the firing pin aperture 25 opens in axial alinement with the liner 16 through which aperture the firing pin 22 projects to a limited extend upon its movement into firing position for engagement with the cartridges primer. In carrying out the present invention provision is made whereby the firing only of safety arnmunition can be accomplished and the firing of a standard or conventional ammunition is precluded. T o this end the construction of the firing chamber is such that a conventional cartridge is positively positioned therein so that its primer is spaced forwardly of the firing position of the firing pin 22 so that it cannot be detonated, and a safety cartridge constuction is provided wherein the primer is located for engagement and thus detonation by the firing To determine the seated or firing position of a round of ammunition the firing chamber 18 is formed with a transaxial surface for abutment by the rim of the cartridge of a round of ammunition inserted therein. In the firearm of FIGS. 1 and 2 the transaxial surface, indicated at 52, is defined by the rear end of the liner 16 and the bordering material of the barrel 14. In addition the construction insures abutment of a cartridge rim with the transaxial surface 52 when the firing chamber is closed. Thus the recess in the recoil plate 2G is fashioned so that it has a transaxial dimension adjacent its forward end which is less than the rim diameter of a standard or conventional cartridge. As shown, the recess in the recoil plate 20 has its lower surface 56a formed so that it converges rearwardly from its forward open end toward the aperture 25. It will be apparent that upon movement of the barrel assembly 14 with respect to the frame 12, from an open or loading position into closed or firing position, the head of a cartridge received therein is moved into engagement with the surface 50a of the recoil plate recess 50. The cartridge is urged forwardly thereby so that its rim abuts the rearwardly facing transaxial surface 52 where it is held until the firearm is broken open. In FIG. 2 the practice firearm is shown with a standard or conventional round of ammunition 54 disposed within the firing chamber 18. It will there be seen that the surface 50a is in engagement with the rearmost portion of the cartridge rim so that the forwardly facing surface of the cartridge rim is held against the rearwardly facing transaxial surface S2 of the forward portion of the firing chamber 18. Also the firing pin carrier 24 is in its forwardmost position and has carried the firing pin 22 into its firing position. It will be seen that the forward end of the firing pin 22 and the primer 55 of the conventional cartridge 54 are spaced apart a predetermined distance as indicated by the letter S. As a result the primer 55 of the conventional cartridge 54 is not struck by the firing pin and no detonation can occur.

In accordance with another aspect of the present invention the safety cartridge 11 for use in the practice firearm 10 is provided. In carrying out this aspect of the invention, the safety cartridge 11 is of the type utilizing the explosive force only of a primer to propel its lightweight projectile and wherein the construction is such that its primer is disposed for engagement and detonation by the firing pin 22. As shown in FIG. 4, the safety cartridge 11 is of the general type disclosed and claimed in my copending application Serial No. 359,647, fled April 14, 1964. It includes a cartridge casing 56 formed of plastic or other lightweight material having a bore 58 extending therethrough. The forward portion 58a of the bore is enlarged for the reception therein of a projectile 60. At its rear end the cartridge casing 56 is formed with a head 62 having a rim 63 for engagement with the transaxial surface 52 of the firing chamber 18 which determines the seated or firing position of the cartridge within the firing chamber. In the rear end of the head 62 the cartridge casing bore terminates in a recess SSb for receiving a primer 64. The recess 58h and the enlarged forward portion 58a of the cartridge bore 58 are interconnected by a bore portion 58C of reduced diameter for effecting venturi action upon the explosive force produced by detonation of the primer 64 for expelling the projectile 60 from the casing 56. In addition to utilizing only that force produced by the primer, the penetrative properties of the projectile are desirably further reduced by fashioning it of lightweight resilient material such, for example, aS rubber or relatively soft plastic. In order to stabilize the flight of the projectile 60, traveling at low velocity, it is formed with a plurality of symmetrically-spaced radial fins 65 that extend rearwardly from its body 66. This projectile construction has been found to effect a substantially flat trajectory for a range on the order of twenty-five feet to thirty feet when propelled by the explosive force resulting from detonation of a small primer.

The rim `63 of the round y1-1 of safety ammunition is cylindrical and extends rearwardly a distance substantially equal to the thickness of the rim of a conventional cartridge. To position its primer 64 for engagement and detonation by the lfiring pin 22 the head 62 of the illustrative round 11 of safety ammunition is extended rearwardly so that the outer end of the 1primer is located a distance equal to for slightly greater than the predetermined distance S indicated in FIG. 2. In addition the cartridge head 62 is complementally formed for reception in the recess 50 of the recoil plate 20. As shown it is of frust-o-conical shape. Thus, when a Safety round so constructed is loaded into the practice firearm 1o the lforward cylindrical portion of the cartridge casing 56 extends into the barrel liner 16, and when the barrel assembly 14 4is moved `in-to closed position with respect to the frame 16, `the outer conical surface of the head 62 is moved into engagement 'with the surface 50a of the recoil plate recess 5@ whereby the cartridge is urged forwardly, with the forwardly facing surface of its rim 63 abutting the transaxial surface 52 of the firing chamber 18, and the practice round is positively positioned for firing. It will be apparent, too, that the peculiar rearward extension of the head 62 and its shape make the safety round readily distinguishable from other ammunition.

The present invention also contemplates the provision of an adapter for selectively converting ya standard firearm `for practice use with safety ammunition as hereinbefore described so that only such ammunition can be fired when the standard firearm is so converted. It is also contemplated that the adapter can be readily removed and the firearm restored tro its normal operating condition. In FIG. 3 there is shown a firearm '70 of the con- 'ventional revolver type. 'It includes a frame 72 which is equipped `with a barrel 7-4, a pistol grip type handle 75, and a conventional tiring mechanism including a hammer 76 mounting a tiring pin 77 and a trigger 78 for releasing the hammer and Ifiring pin for movement from cooked to firing positions. Intermediate its ends, the frame 72 is formed with an appropriate opening 79 for the reception of a cylinder (not shown). In carrying out this aspect of the present invention an adapter 80 is provided for alternative use in place of the conventional cylinder. The adapter `80 thus includes a block l82 defining a chamber 84 for the reception of the cylindrical forward end portion of the cartridge 456 of a round of safety ammunition 111. In the same manner as a conventional cylinder, the block 82 is adapted to be supported -in place in the opening 79 of the frame 7-2 upon an extrac-tor pin 86. T-he block 82 is coaxially counterbored to define a transaxial surface y88 about the rear end of the chamber '84 -for engagement by the cartridge rim 6-3. The adapter also includes a recoil plate 90 which has a Vrecess 92 to receive the rearwardly extended head 62 of the cartridge 11. The recoil plate 90 has an aperture 94 therein opening into the rear end of the recess 92 through which the firing pin 77 is projected for engagemen-t with the primer `64 o-f the safety round 11. For purposes of loading and unloading, the recoil plate 90 is mounted for movement with respect to the adapter block '82. In this instance mounting is effected by way of a hinge 96.

From the foregoing it be seen that the transaxial surface 88 of the adapter S0 is disposed in predetermined spaced relation to the firing position of the firing -pin 77. Thus, fwhen the firearm is converted for safety ammunition use, a round of conventional ammunition inserted therein will be urged into seated position against the transaxial surface 88 when the recoil plate 90 is moved into operative position with respect to the block 82. Thus the primer of a conventional cartridge is held in spaced relation forwardly of the firing position of the firing pin so that detonation is precluded. -For purposes of illustration the exemplary ad-apter has been shown with only one cartridge receiving chamber 84. It will be apparent, however, that it can 4be provided with a plurality of such chambers and can be fashioned of cylindrical shape and appropriately formed for rotary indexing movement by the revolving mechanism of the revolver to bring successive chambers into firing position.

I claim as my invention:

'1. A cartridge for use in a direarm having a firing pin movable a predetermined distance between cocked and firing positions and having means defining a firing chamber having a rearwardly facing transaxial surface for abutment by a cartridge rim to determine the seated position thereof and into which the firing pin is projected with its forward end stopping in its firing position a predetermined distance rearwardly of said surface which distanoe is substantially greater than the rim thickness of a conventional cartridge, said cartridge comprising a cylindrical casing of any standard caliber having a forwardly-opening projectile-receiving recess and terminating -at its rear end in a rim for engagement with the transaxial surface of the firing chamber, said rim extending radially from said cylindrical casing at its rear end and rearwardly approximately the same extent as a standard rim of said standard caliber, a lfrusto-conical head portion integral with said rim, said head having a portion extending rearwardly of said rim a distance substantially greater than the axial thickness of .a head of a conventional cartridge of said caliber whereby said car- -tridge is engaged iby said firing pin in its firing position, said head portion having an axial bore therethrough communicating at its forward end with said projectile recess for receiving and holding a primer in rearwardly disposed relation to said rim with the rearward part of said primer extending rearwardly of the back of said head .and in position for engagement by the firing pin upon movement thereof into firing position -whereby to detonate the primer.

2. A cartridge for use in a rearm having Ia firing pin movable a predetermined distance between cooked and firing positions and having means defining a firing chamber having a rearwardly facing transaxial surface for abutment by a cartridge rim to determine the seated position thereof and into which the tiring pin is projected with its forward end stopping in Iits firing position a predetermined distance rearwardly of said surface which distance is substantially greater than the rim thickness of a conventional cartridge, said firing chamber also having a lower surface tapering upwardly and rearw-ardly from the outer periphery of said transaxial surface toward said firing pin, said cartridge comprising a cylindrical casing of any standard caliber having a forwardlyopening projectile-receiving recess and terminating at it-s rear end in a rim portion defining a forwardly-facing surface for engagement with the transaxial surface of the rfiring chamber, said rim extending radially from said cylindrical casing at its rear end and rearwardly approximately the same extent as a standard rim lof said standard caliber, a frusto-conical head portion integral with said rim, said 'head extending rearwardly of said rim portion a distance substantially greater than the axial thickness of a head of .a conventional cartridge of said caliber, and being complementally formed for reception in said firing chamber in engagement with said tapered lower surface of said chamber whereby said cartridge is engaged by said Ifiring pin in its tiring position, said head portion having an axial bore therethrough communicating at its forward end with said projectile recess ifor receivi-ng and holding a primer in rearwardly disposed relation to said rim with the rearward part of said primer extending rearwardly of the back of said head and in position for engagement by the firing pin upon movement thereof into firing position whereby to detonate the primer.

3. A. cartridge for use i-n a firearm having Ia firing pin -movable a predetermined distance -between cocked and firing positions and having means defining a firing chamber having a rearwardly facing transaxial surface for .abutment by a cartridge rim to determine the seated position thereof and including a recoil plate having a portion adapted to engage lthe cartridge to insure abutment of its rim with said transaxial surface, the recoil plate defining the rearward limits of said chamber and having an aperture therein through which the tiring pin is projected with its forward end stopping in its firing position a predetermined distance rearwardly of said transaxial surface which distance is substan-tially greater than the rim thickness of a conventional cartridge, said cartridge comprising a cylindrical casing of any standard caliber having a forwardly-opening projectile-receiving recess, a rim portion defining a forwardly facing surface for engagement with said transaxial surface of the firing chamber, said rim extending rearwardly approximately the same ex-tent as a standard rim of said standard caliber, and a frusto-conical head portion integral with and extending rearwardly from said rim having an axial thickness substantially equal to greater than the axial thickness of a head of a conventional cartridge of said caliber and being c-omplementally formed for engagement with said recoil plate to insure abutment of said rim with said transaxial surfaoe, said head having an axial bore there-through communicating at its forward end with said projectile recess for receiving and holding a primer in rearwardly disposed relation to said rim with the rearward part of said primer extending rearwardly of the back of said head and in position for engagement by the fir-ing pin upon movement thereof i-nto firing position whereby to detonate the primer.

4. A cartridge for use in a firearm having a firing pin movable a predetermined distance between cocked and firing positions and having me-ans defining a 'firing chamber having a rearwardly :facing transaxial surface for abutment by a cartridge rim to determine the seated position thereof and including a recoil plate forming a truste-conical chamber adapted to engage the cartridge to insure abutment of the cartridge rim with said transaxial surface, the recoil plate having an aperture therein through Which the tiring pin is projected into the rear portion `of said frusto-conical chamber with its forward end stopping in its tiring position la predetermined distance rearwardly of said transaxial surface which distance is substantially greater than the rim thickness of a conventional cartridge, said cartridge comprising a cylindrical casing having a forwardly opening projectilereceiving recess, a rim portion defining a forwardly facing surface for engagement with the transaxial surface of the ring chamber, and a 4frusto-oonical head extending rearwardly of said rim, said rim portion extending rearwardly approximately the same extent as a standard rim of said standard caliber, and Ia frusto-oonical head portion integral with and extending rearwardly of said rim portion a distance substantially greater than the axial thickness of a head of a conventional cartridge of said caliber for engagement with the walls of the frusto- CTI References Cited by the Examiner UNITED STATES PATENTS Re. 18,252 `11/1931 Alden 102-38 703,840 7/ 1902 Scott 102-38 3,157,126 11/1964 Blondeau 10\292.5

FOREIGN PATENTS 1,028,910 4/ 1958 Germany.

BENJAMIN A. BORCHELT, Primary Examiner.

R. F. STAHL, Assistant Examiner. 

1. A CARTRIDGE FOR USE IN A FIREARM HAVING A FIRING PIN MOVABLE A PREDETERMINED DISTANCE BETWEEN COCKED AND FIRING POSITIONS AND HAVING MEANS DEFINING A FIRING CHAMBER HAVING A REARWARDLY FACING TRANSAXIAL SURFACE FOR ABUTMENT BY A CARTRIDGE RIM TO DETERMINE THE SEATED POSITION THEREOF AND INTO WHICH THE FIRING PIN IS PROJECTED WITH ITS FORWARD END STOPPING IN ITS FIRING POSITION A PREDETERMINED DISTANCE REARWARDLY OF SAID SURFACE WHICH DISTANCE IS SUBSTANTIALLY GREATER THAN THE RIM THICKNESS OF A CONVENTIONAL CARTRIDGE, SAID CARTRIDGE COMPRISING A CYLINDRICAL CASING OF ANY STANDARD CALIBER HAVING A FORWARDLY-OPENING PROJECTILE-RECEIVING RECESS AND TERMINATING AT ITS REAR END IN A RIM FOR ENGAGEMENT WITH THE TRANSAXIAL SURFACE OF THE FIRING CHAMBER, SAID RIM EXTENDING RADIALLY FROM SAID CYLINDRICAL CASING AT ITS REAR END AND REARWARDLY APPROXIMATELY THE SAME EXTENT AS A STANDARD RIM OF SAID STANDARD CALIBER, A FRUSTO-CONICAL HEAD PORTION INTEGRAL WITH SAID RIM, SAID HEAD HAVING A PORTION EXTENDING REARWARDLY OF SAID RIM A DISTANCE SUBSTANTIALLY GREATER THAN THE AXIAL THICKNESS OF A HEAD OF A CONVENTIONAL CARTRIDGE OF SAID CALIBER WHEREBY SAID CARTRIDGE IS ENGAGED BY SAID FIRING PIN IN ITS FIRING POSITION, SAID HEAD PORTION HAVING AN AXIAL BORE THERETHROUGH COMMUNICATING AT ITS FORWARD END WITH SAID PROJECTILE RECESS FOR RECEIVING AND HOLDING A PRIMER IN REARWARDLY DISPOSED RELATION TO SAID RIM WITH THE REARWARD PART OF SAID PRIMER EXTENDING REARWARDLY OF THE BACK OF SAID HEAD AND IN POSITION FOR ENGAGEMENT BY THE FIRING PIN UPON MOVEMENT THEREOF INTO FIRING POSITION WHEREBY TO DETONATE THE PRIMER. 